Review: Bluetooth Connectivity

Don Bradbury looks at this increasingly popular wireless medium for setting up ad-hoc device networks

Product	Bluetooth Adapters
Company	Belkin Corp and IVT Corp
Web	www.belkin.com www.ivtcorporation.com
Price	£7.99 and around £5 resp
We like	Useful connectivity
We don't like	Protracted Bluetooth installation under Windows Vista; not as fast as a good WiFi connection
Rating	8/10
Requirements

Wireless peripherals connectivity is not restricted to WiFi Internet and the usual modes of connection through wireless modem/routers. We've had InfraRed for a long time, and recently the Bluetooth standard has steadily gained favour, not only for it's ostensible ease of setup but also, increasingly, for it's versatility, and more recently its useful wireless range.

We looked at the Belkin Bluetooth device, built on the usual USB 2.0 model, as one example of the range of adapters on offer from sundry manufacturers, and we pressed an unbranded and even more inexpensive alternative into service as a second Bluetooth dongle to see how it compared. Installation of the former on a host Vista Home Premium computer, while ostensibly easy, took a surprising length of time to complete, with some convolutions we did not anticipate.

However, after initial setup with the Belkin dongle acting as primary device on the computer, the unbranded (subsequently revealed to be an IVT Corp product) was quickly added to sundry devices for networking, including a second PC access point, a USB printer, a wireless mouse, and a PDA. Other hopefuls could include a suitable digital camera, mobile phone, or a headset for example.

These days, rather than the meagre 10 metre range we used to see for Bluetooth, 100 metre is now common. This advance leads to the feasibility of connecting PCs together in an ad-hoc network that, while not as fast as those connected via a router's WLAN, is sufficient for secure file transfer and the use of other services on the PCs that are so linked.

Thus, while your WiFi connection may leave more distant PCs out in the cold, so to speak, a Bluetooth-connected PC may be able to connect usefully to the WiFi-fed PC. In effect, then, the out-of-range connected device has benefited from the Bluetooth booster signal. In addition, of course, the Bluetooth connection has been established at substantially lower cost than adding a WiFi adapter to the second PC, which may be necessary with an older computer which did not come WiFi enabled.

The Science

Bluetooth technology operates in the unlicensed industrial, scientific and medical (ISM) band at 2.4 to 2.485 GHz, using a spread spectrum, frequency hopping, full-duplex signal at a nominal rate of 1600 hops/sec. The technology's adaptive frequency hopping (AFH) capability is designed to reduce interference between wireless technologies sharing the 2.4 GHz spectrum.

As far as connectivity is concerned, it relies on radio frequency radiation - unlike InfraRed which is limited to short range line-of-sight connections, and these days is therefore not so much used except perhaps for the odd print job. But even for this duty, Bluetooth does a better job, not only not requiring line-of-sight but also providing a potentially more stable connection, not to mention the greater range of transmission. Some aspects of Bluetooth, though, can prove a little more difficult to set up in the first place; establishing services for the connection and so on.

The crucial aspect of Bluetooth setup lies in the act of "pairing" devices, a process that lets the devices talk to each other over the Bluetooth link. After the devices have been detected, added, and paired, the entire Bluetooth neighbourhood you have set up can be "investigated", and the services the devices provide established. The IVT Corp device's software lined up the following options for us.

Our second laptop PC was quickly and easily added to the network neighbourhood, and after pairing, the Bluetooth environment indicated the fact that connectivity had been established by means of twin arrows, as shown in the graphic.

During FTP file transfer between the two linked PCs, and after indicating the security level required, the add-on PC displayed notification that the first computer had established an FTP connection and then, when the service was completed, a disconnection notice, as shown below.

We have to say we rather liked the IVT software. BlueSoleil, as it is dubbed (Soleil means "the sun"), is a set of Bluetooth Application Profiles for implementation on the Windows operating system, and it's compliant with the latest Bluetooth SIG specifications. The v3 implementation shows a dark blue space-like background "intended to create a sense of depth and intrigue", according to IVT. The host device is depicted as a golden globe in the centre, with the remote devices that are within range displayed as planets orbiting the "Sun". BlueSoleil is intended to take the complications out of creating Bluetooth connections and in our experience we think it succeeds in that aim. The intuitive graphics makes it user-friendly for both control and operation.

So this software displayed the link to the first computer, together with the list of options and services which were neatly laid out in its menu system. Cheap as it was, we could not fault the IVT Corp Bluetooth dongle and it's support software; it did what is was supposed to do, cooperating nicely with Belkin's Bluetooth adapter which also did it's bit.

This cooperation, we should point out, is not necessarily guaranteed between devices of different manufacture. Epson Corp, for example, will wash their hands of you over any technical queries concerning their printers if the adapters are not of their own brand. A rather mean stance, you might think, but then things would not be within their own control otherwise, and it's therefore somewhat understandable.

Not the fastest wireless connectivity medium there is, perhaps, but the IVT Soleil claims 5Mbps in it's latest (downloadable) incarnation, and that's a usable speed.

In conclusion

Setting up and using Bluetooth as an alternative connectivity medium can be both useful and rewarding. What's more, as we have discovered, it can be very inexpensive to implement. Even cheap unbranded Bluetooth adapters can, in our experience, give very satisfactory service. Bluetooth setup may be something of a black art with certain devices, but most are added to the Bluetooth neighbourhood quickly and easily, thereafter to perform their magic via their own brand of wireless networking. It's certainly worth taking a look if you have the applications.

 

Don Bradbury